Nonparametrie recursive estimator for mean residual life and vitality function under dependence conditions

In this paper, we develop a nonparametrie recursive estimator for the vitality and mena residual life function, based on kernel density estimators under mixing dependence conditions. The consistency and asymptotic normality of the estimator are established, under suitable regularity conditions. It is also shown that the Integrated Mean Squared Error converges to zero. The paper is concluyed with some simulation results.     

The Exponentiated G Poisson Model

We study a new family of distributions defined by the minimum of the Poisson random number of independent identically distributed random variables having a general exponentiated G distribution. Some mathematical properties of the new family including ordinary and incomplete moments, quantile and generating functions, mean deviations, order statistics and their moments, reliability, and Shannon entropy are derived. Maximum likelihood estimation of the model parameters is investigated. Two special models of the new family are discussed. We perform an application to a real data set to show the potentiality of the proposed family.     

The performance of the truncated mixed control chart

Abstract

When the mixed chart proposed by Aslam et al. (2015 Aslam, M., M. Azam, N. Khan, and C.-H. Jun. 2015. A mixed control chart to monitor the process. International Journal of Production Research 53 (15):4684–93. doi:10.1080/00207543.2015.1031354.[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]) is in use, the sample items are classified as defective or not defective and, depending on the number of defectives, the quality characteristic X of the sample items are also measured. In this case, an Xbar chart decides the state of the process. The previous conforming/non-conforming classification truncates the X distribution and, because of that, the mathematical development to obtain the ARLs is complex. Aslam et al. (2015 Aslam, M., M. Azam, N. Khan, and C.-H. Jun. 2015. A mixed control chart to monitor the process. International Journal of Production Research 53 (15):4684–93. doi:10.1080/00207543.2015.1031354.[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]) didn’t pay attention to the fact that the X distribution is truncated and, due to that, they obtained incorrect ARLs.     

HERD BEHAVIOR IN FINANCIAL MARKETS: AN EXPERIMENT WITH FINANCIAL MARKET PROFESSIONALS

We study herd behavior in a laboratory financial market with financial market professionals. An important novelty of the experimental design is the use of a strategy‐like method. This allows us to detect herd behavior directly by observing subjects' decisions for all realizations of their private signal. In the paper, we compare two treatments: one in which the price adjusts to the order flow in such a way that herding should never occur, and one inwhich the presence of event uncertainty makes herding possible. In the first treatment, subjects seldom herd, in accordance with both the theory and previous experimental evidence on student subjects. A proportion of subjects, however, engage in contrarianism, something not accounted for by the theory. In the second treatment, the proportion of herding decisions increases, but not as much as the theory would suggest. Moreover, contrarianism disappears altogether. In both treatments, in contrast with what theory predicts, subjects sometimes prefer to abstain from trading, which affects the process of price discovery negatively. (JEL: C92, D82, G14)     

Stability of risk preferences and the reflection effect of prospect theory

Are risk preferences stable over time? To address this question we elicit risk preferences from the same pool of subjects at two different moments in time. To interpret the results, we use a Fechner stochastic choice model in which the revealed preference of individuals is governed by some underlying preference, together with a random error. We take cumulative prospect theory as the underlying preference model (Kahneman and Tversky, Econometrica 47:263–292, 1979; Tversky and Kahneman, Journal of Risk and Uncertainty 5:297–323, 1992). We observe that the aggregate pattern of preferences is very similar in both sessions, and it matches the results reported in the literature. Most subjects are risk averse for gains, and risk seeking for losses. However, the subjects that jointly agree with the reflection effect of prospect theory are around 50%. The percentage of individuals that change their responses across sessions is quite high, 63%. Estimating the stochastic choice model we find that 72% of the subjects have an underlying preference which agrees with the reflection effect of prospect theory. The remaining 28% are mainly classified as risk averse for both gains and losses. The results reinforce the empirical validity of the reflection effect. Deviations from the reflection effect can be attributed to noise, as well as to the existence of a fraction of risk averse subjects.     

The Dynamics of Welfare Policy‐Making in South Korea: Social Movements as Policy Entrepreneurs*

This paper analyzes the role of social movements in the creation and evolution of a welfare state in South Korea. We begin with a theoretical overview of the existing works on policy change, highlighting concepts such as ideas, policy paradigms, and windows of opportunity. We then examine state institutions, hegemonic policy paradigms, and the specific dynamics of welfare policy‐making during South Korea’s authoritarian period (1961–1987). Next, characterizing the democratic transition in 1987 and the economic crisis of 1997–1998 as “windows of opportunity,” we probe how social movements emerged as “policy entrepreneurs” and played crucial roles in building welfare institutions and promoting welfare policies. In particular, we focus on the role of social movements in legislating the National Basic Livelihood Security Act in 1999 and consolidating fragmented health insurance systems in 2000. We conclude that social movements in democratized South Korea have assumed the role of policy entrepreneurs, filling the vacuum left by the central government and elite bureaucrats in the field of social welfare policy‐making.     

Testing uniformity for the case of a planar unknown support

A new test is proposed for the hypothesis of uniformity on bi‐dimensional supports. The procedure is an adaptation of the “distance to boundary test” (DB test) proposed in Berrendero, Cuevas, & Vázquez‐Grande (2006). This new version of the DB test, called DBU test, allows us (as a novel, interesting feature) to deal with the case where the support S of the underlying distribution is unknown. This means that S is not specified in the null hypothesis so that, in fact, we test the null hypothesis that the underlying distribution is uniform on some support S belonging to a given class ${\cal C}$ . We pay special attention to the case that ${\cal C}$ is either the class of compact convex supports or the (broader) class of compact λ‐convex supports (also called r‐convex or α‐convex in the literature). The basic idea is to apply the DB test in a sort of plug‐in version, where the support S is approximated by using methods of set estimation. The DBU method is analysed from both the theoretical and practical point of view, via some asymptotic results and a simulation study, respectively. The Canadian Journal of Statistics 40: 378–395; 2012 © 2012 Statistical Society of Canada     

EVALUATING A BILINGUAL EDUCATION PROGRAM IN SPAIN: THE IMPACT BEYOND FOREIGN LANGUAGE LEARNING

Bilingual education programs, which consist of doing a substantial part of the instruction in a language different from the native language of the students, exist in several countries like the United States, India, and Spain. While the economic benefits of knowing a second language are well established, the potential effects over the learning of other subjects have received much less attention. We evaluate a program that introduced bilingual education (in English and Spanish) in primary education in a group of public schools of the Madrid region in 2004. Under this program, students not only study English as a foreign language but also some other subjects (at least Science, History, and Geography) are taught in English. In order to evaluate the program, a standardized test for all sixth grade students in Madrid on the skills considered “indispensable” at that age is our measure of the outcome of primary education. Our results indicate that there is a clearly negative effect on the exam results for the subject taught in English, for children whose parents have less than upper secondary education. This negative effect is a composite of two phenomena: the effect of the program on the student's knowledge of the subject and a reflection of the student ability to do the test in their native language when English is the medium of instruction. Although we are not able to separate quantitatively these two effects, the composite effect has a relevant interest, because the results for exams taken in Spanish are the measures that determine academic progression in the Spanish system. In contrast with the previous result, there is no significant effect for anyone on mathematical and reading skills, which were taught in Spanish. (JEL H40, I21, I28)     

Is the beautiful always so good? Influence of physical attractiveness on the social perception of sexual harassment / ¿Es lo bello siempre tan bueno? Influencia del atractivo físico en la percepción social del acoso sexual

Research has shown that the perception of sexual harassment depends on factors such as gender, the situational context, the type of harassment, the ideology of the perceiver, the physical attractiveness of the harasser and victim and the relationship between them. This study focuses on examining the influence of physical attractiveness in the perception of a situation like sexual harassment. Through a questionnaire, 205 participants read a scenario in which a male worker (attractive vs. unattractive) engaged in gender harassment against a female colleague (attractive vs. unattractive). The participants then answered the measurements on the perception of harassment, responsibility, motivation and ideology. The main results were that the situation was more often perceived as sexual harassment when the victim of the harassment was physically attractive than when she was unattractive. Furthermore, the higher the participants’ acceptance of harassment myths the more they tended to blame the victim. We can conclude from this study the importance of the influence of certain myths or preconceived ideas about sexual harassment, which are found in both men and women, on how these situations are perceived.     

Set estimation and nonparametric detection

The authors consider the estimation of a set S ? R^d from a random sample of n points. They examine the properties of a detection method, proposed by Devroye & Wise (1980), which relies on the use of a “naive” estimator of S defined as a union of balls centered at the sample points with common radius ?_n. They obtain the convergence rate for the probability of false alarm and show that the smoothing parameter ?_n can be used to incorporate some prior information on the shape of S. They suggest two general methods for selecting ?_n and illustrate them with a simulation study and a real data example.